The halo sign is a CT finding of ground-glass opacity surrounding a pulmonary nodule or mass. The reversed halo sign is a focal rounded area of ground-glass opacity surrounded by a crescent or complete ring of consolidation. In severely immunocompromised patients, these signs are highly suggestive of early infection by an angioinvasive fungus. The halo sign and reversed halo sign are most commo...

We present an extensive parameter survey to study the influence of halo mass profiles on the development of tidal tails in interacting disk galaxies. We model the galaxies using a fixed exponential disk with a central bulge and vary the halo potential over a range of parameters using both the Hernquist and NFW mass distributions, probing the effect of the halo mass, extent and concentration. We...

The gravitational microlensing experiments in the direction of Large Magellanic Cloud (LMC) predict a large amount of white dwarfs (∼ 20%) filling the galactic halo. However, the predicted white dwarfs have not been observed at the galactic halo. To interpret the microlensing results and resolving the mentioned problems, we use the hypothesis of spatially varying mass function of MACHOs, propos...

SLAC-PUB-6379 October 1993 W Simulation of the Beam Halo from the Beam-Beam Interaction T. Chen, J. Irwin and R. Siemannt Stanford Linear Accelerator Center, Stanford University, Stanford, CA94309 Abstract: A new technique for simulating the beam halo in circular e+ecolliders is introduced, tested, and applied. Amplitude space is divided into core and halo regions, and only halo particles are t...

We have carried out a detailed abundance analysis for 21 elements in a sample of four RGB stars in the outer halo globular cluster NGC 7492 (RGC 25 kpc); we find [Fe/H] = −1.82 dex inferred from Fe I lines (−1.79 from Fe II) using high dispersion (R=λ/∆λ=35,000) spectra obtained with HIRES at the Keck Observatory. Most elements show no sign of star-to-star variation within our limited sample. W...

The halo structure at high Galactic latitudes near both north and south poles is studied using SDSS and SuperCOSMOS data. For the southern cape halo, the archive of SuperCOSMOS photographic photometry sky survey is used. The coincident source rate between SuperCOSMOS data in BJ band from 16 .5 to 20.5 and SDSS data is about 92%, as from a common sky area in the south. While that in RF band is a...

If the Galactic rotation speed at the Solar circle is ∼ 200 km s or smaller, which is supported by several recent studies, the rotation curve of the Galaxy could be declining in the outermost region. Motivated by this, we investigate the effect of such declining rotation curve on the estimate of the MACHO mass and the fractional contribution of the MACHOs to the Galactic dark halo. Using Hernqu...

Surface photometry detections of red and exceedingly faint halos around galaxies have resurrected the old question of whether some non-negligible fraction of the missing baryons of the Universe could be hiding in the form of faint, hydrogen-burning stars. The optical/near-infrared colours of these red halos have proved very difficult to reconcile with any normal type of stellar population, but ...

The peak-background split argument is commonly used to relate the abundance of dark matter halos to their spatial clustering. Testing this argument requires an accurate determination of the halo mass function. We present a Maximum Likelihood method for fitting parametric functional forms to halo abundances which differs from previous work because it does not require binned counts. Our conclusio...

We derive mass functions for halo red dwarfs (stars just massive enough to burn hydrogen) with varying assumptions about metallicity and about possible unresolved binaries in the sample. The mass functions are obtained from the luminosity function of a sample of 114 local halo stars in the USNO parallax survey (Dahn et al. 1995); we use stellar models of Alexander et al. (1996). We find that th...